In a previous entry, I was lamenting the fact that each of my themes relies on two different stylesheets which effectively rules out using an on-the-fly style switcher.
Well, Paul Sowden comes to my rescue. He writes:
"You should add the @import rule to the begining of each external sheet.
The document would have a list of alternate sheets, and inside each of the alternate sheets that are linked (the basic ones) you put the @import rule linking to the more advanced sheet on the first line.
Hey presto, old browsers are happy, new browsers are happy, and people can change sheets actually "on the fly"."
Excuse me while I slap my forehead: it’s so obvious now that somebody has pointed it out to me.